iankelling.org Git - distro-setup/blob - switch-mail-host

   1 #!/bin/bash
   2
   3 err-bash-trace() {
   4   local -i argc_index=0 frame i start=${1:-0} max_indent=8 indent
   5   local source
   6   local extdebug=false
   7   if [[ $(shopt -p extdebug) == *-s* ]]; then
   8     extdebug=true
   9   fi
  10   for ((frame=0; frame < ${#FUNCNAME[@]}-1; frame++)); do
  11     argc=${BASH_ARGC[frame]}
  12     argc_index+=$argc
  13     ((frame < start)) && continue
  14     if (( ${#BASH_SOURCE[@]} > 1 )); then
  15       source="${BASH_SOURCE[frame+1]}:${BASH_LINENO[frame]}:"
  16     fi
  17     indent=$((frame-start + 1))
  18     indent=$((indent < max_indent ? indent : max_indent))
  19     printf "%${indent}s↳%sin \`%s" '' "$source" "${FUNCNAME[frame]}"
  20     if $extdebug; then
  21       for ((i=argc_index-1; i >= argc_index-argc; i--)); do
  22         printf " %s" "${BASH_ARGV[i]}"
  23       done
  24     fi
  25     echo \'
  26   done
  27   return 0
  28 }
  29
  30
  31 err-catch() {
  32   set -E; shopt -s extdebug
  33   _err-trap() {
  34     err=$?
  35     exec >&2
  36     set +x
  37     echo "${BASH_SOURCE[1]}:${BASH_LINENO[0]}: \`$BASH_COMMAND' returned $err"
  38     err-bash-trace 2
  39     set -e # err trap does not work within an error trap
  40     "${_errcatch_cleanup[@]:-:}" # note :-: is to be compatible with set -u
  41     echo "$0: exiting with code $err"
  42     exit $err
  43   }
  44   trap _err-trap ERR
  45   set -o pipefail
  46 }
  47 err-catch
  48
  49 usage() {
  50   cat <<EOF
  51 Usage: ${0##*/} OLD_HOST NEW_HOST
  52
  53 Turn off mail receiving on OLD_HOST, run btrbk to move mail to NEW_HOST,
  54 turn on mail receiving on NEW_HOST.  Assumes we want to move all
  55 filesystems unless passing -o.
  56
  57 -o         Only btrbk /o, instead of all filesystems.
  58 -h|--help  Print help and exit.
  59
  60 I used to adjust home network dns so NEW_HOST resolves locally if it is
  61 on the local network, but its simpler just not to and just rely
  62 on the internet. Email can wait.
  63
  64 Note: Uses GNU getopt options parsing style
  65 EOF
  66   exit $1
  67 }
  68
  69 restore_new_btrbk=false
  70 restore_old_btrbk=false
  71 cleanup() {
  72   if $restore_new_btrbk; then
  73     $new_shell sudo systemctl start btrbk.timer
  74   fi
  75   if $restore_old_btrbk; then
  76     $old_shell sudo systemctl start btrbk.timer
  77   fi
  78 }
  79 _errcatch_cleanup=cleanup
  80
  81 pre="${0##*/}:"
  82 m() { printf "$pre %s\n"  "$*"; "$@"; }
  83 e() { printf "$pre %s\n"  "$*"; }
  84
  85 ##### begin command line parsing ########
  86
  87 temp=$(getopt -l help owh "$@") || usage 1
  88 mp_args="-m /o,/q,/a"
  89 eval set -- "$temp"
  90 while true; do
  91   case $1 in
  92     -o) mp_args="-m /o"; shift ;;
  93     -h|--help) usage ;;
  94     --) shift; break ;;
  95     *) echo "$0: Internal error! unexpected args: $*" ; exit 1 ;;
  96   esac
  97 done
  98
  99
 100 (( $# == 2 )) || usage 1
 101
 102 old_host=$1
 103 new_host=$2
 104 source /a/bin/bash_unpublished/source-state
 105
 106 if [[ $old_host != $MAIL_HOST ]]; then
 107   read -p "warning: \$old_host != \$MAIL_HOST: $old_host != $MAIL_HOST, proceed? y/N "
 108   if [[ $REPLY != [yY] ]]; then
 109     exit 1
 110   fi
 111 fi
 112
 113 if [[ $new_host == "$HOSTNAME" ]]; then
 114   localhost_new=true
 115   new_shell=
 116 else
 117   localhost_new=false
 118   new_shell="ssh $new_host"
 119 fi
 120
 121 old_shell="ssh $old_host"
 122 if [[ $old_host == "$HOSTNAME" ]]; then
 123   old_shell=
 124 fi
 125
 126 if [[ ! $new_host || ! $old_host ]]; then
 127   echo "$0: bad args. see script"
 128   exit 1
 129 fi
 130
 131
 132 source /a/bin/bash_unpublished/source-state
 133
 134
 135 new_hostname=$($new_shell hostname)
 136
 137 ########### end initial processing, begin actually modifying things ##########
 138
 139 if $new_shell systemctl is-active btrbk.timer; then
 140   m $new_shell sudo systemctl stop btrbk.timer
 141   restore_new_btrbk=true
 142 fi
 143 if $old_shell systemctl is-active btrbk.timer; then
 144   m $old_shell sudo systemctl stop btrbk.timer
 145   restore_old_btrbk=true
 146 fi
 147
 148 btrbk_test="systemctl is-active btrbk.service"
 149 while [[ $($new_shell $btrbk_test) != inactive ]] || [[ $($old_shell $btrbk_test) != inactive ]]; do
 150   echo "$0: btrbk is running on new or old host. sleeping for 8 seconds"
 151   sleep 6
 152   echo "$0: testing for btrbk activity in 2 seconds"
 153   sleep 2
 154 done
 155
 156 # ensure these are unused before doing anything
 157
 158 e "umounting /m and /o via $new_shell"
 159 $new_shell bash -xs <<'EOF'
 160 set -eE
 161 if mountpoint -q /m; then sudo umount /m; fi
 162 if mountpoint -q /o; then sudo umount /o; fi
 163 EOF
 164
 165 # previously, I was checking to see if the new mail host
 166 # is on my home network, then changing my home dns
 167 # to resolve on the local network, so that I didnt
 168 # have to send traffic out to the internet or rely
 169 # on that. However, that breaks for a laptop that roams.
 170 # So, we could have a cronjob that updates that dns,
 171 # however, another solution is to just use ipv6,
 172 # and I prefer that.
 173 #
 174 # TODO: enable ipv6 for email. exim config setting disables it.
 175 # need to add vpn support. need to add firewall / routing.
 176 # I think exim will try ipv6 first, so no need to disable
 177 # ipv6 i think.
 178
 179 m $old_shell /a/exe/primary-setup $new_hostname
 180
 181 if $localhost_new; then
 182   m btrbk-run -v -s $old_host $mp_args
 183 else
 184   m btrbk-run -v -t $new_host $mp_args
 185 fi
 186
 187 m $new_shell /a/exe/primary-setup $new_hostname